Speedometer-magnet mounting



Nov. 2 1926.

J. Z BATY SPEEDOMETER MAGNET MOUNTING Filed Dec. 12. 1924 lNVENTOR Jfimguh Zubg BY [7 9") my: ATTORNEYS Patented Nov. 2, 1926.

time STATES means PAT NT or-Pics.

JOSEPH ZUBA'TY, or rninr, Mic ela, Assrenon TO ac. srAnK; ewe COMPANY. OF FLINT, MICHIGAN, COMPANY or MICHIGAN.

srEEIJoMirrnR-MAennT MOUNTING.

Application filed December 12, 1924. Serial No. 755,478.

This invention relates to speedometers, and is illustrated as embodied in a magnetic speedometer. An object of the invention is to provide for holding the arms of the controlling magnet firmly with extreme accuracy with respect to the axis of the inclicating element. Preferably the arms are held by clamps drawing them firmly against positioning surfaces on the frame which supports the indicating element, these surfaces engaging the insides and the edges of the arms.

Desirable details of construction, and the advantage of the described arrangement, will be'apparent from the following description of the illustrative embodiment of the invention shown in the accompanying drawings, in which:

Figure 1 is a side elevation of the magnet and the indicating element and the frame which supports them;

Figure 2 is a front elevation of the same parts; and

Figure 3 is a section of the line 33 of Figure 1, showing in detail the clamping means.

The particular speedometer shown, which is a speedometer with the casing and odometer mechanism removed, includes various parts supported on a frame made up in two parts, a main frame 10 and a sub-frame 12 adj ustably mounted on the main frame and carrying an indicating element or dial 14: which is angularly movable against the resistance of a hair spring 16. The indicating element is controlled by variations in a magnetic field caused by an iron rotor (not shown) within and coaxial with respect to element 14., and which is driven in the usual manner by a flexible shaft 18.

The above-mentioned magnetic field is produced by a magnet having arms 20 and 22 on opposite sides of element 14 (and of the iron rotor). Each arm of the magnet is accurately positioned with respect to the axis of the indicating element and the rotor, by engagement of the edge nearest frame 10 (the right-hand edge in Figure 3) with a carefully machined gage surface at 24 on a lug 26, shown integral with frame 10, and by engagement of its inside surface with a carefully machined gage surface at 28, also shown as being formed on lug 26.

Each arm of the magnet is drawn firmly against these surfaces by a clamp member 30,

having a hook 32 at its end engaging the front edge of the magnet arm, and drawn tightly into place by a screw 34 threaded into a tapped opening in lug 26. It will be noted that screw 34 extends at an acute.

angle to the magnet arm (see Figure 3); so that it operates the hook 32 to draw the arm firmly against surface 24 at the same time that it crowds the arm against surface 28.

By the provision of surface 28 against which the clamp 30 draws the magnet arm, it will be obvious that no great care is needed in making the magnet with the correct spread of arms. If the spread is too great, the clamp will draw the arms toward each other and into engagement with the faces 28. The angularity of the face of the clamp and the angular direction of the screw 34 insures an engagement of the magnet arm with both faces, and therefore a fixed position of the magnet relative to the diameter of part 14.

While one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope to that particular embodiment, or otherwise. than by the terms of the appended claims.

I claim:

1. A speedometer comprising, in combination, a frame, a magnetically-controlled angularly-movable speed-indicating device supported on the frame, a magnet having arms on opposite sides of said device, lugs on the frame having finished positioning surfaces engaging the insides of the arms and the edges of the arms next the frame, and clamps drawing the arms toward each other and toward the frame to clamp them firmly in predetermined positions with respect to the axis of the speed indicating device.

2. A speedometer comprising,in combina tion, a frame, a magnetically-controlled angularly-movable speed-indicating device supported on the frame, a magnet having arms on opposite sides of said device, lugs on the frame having finished positioning surfaces engaging the insides of the arms and the edges of the arms next the frame, angle clamps hooking over the front edges ofthe magnet arms and extending across the outsides of the arms, and screws passing through the clamps and threaded into the lugs for drawing the clamps inward to hold the magnet arms firmly against the positioning surfaces on their inner sides, the screws being inclined to draw the clamps and magnet arms toward the frame to hold the magnet arms firmly against the positioning surfaces engaging their edges.

3. In a measuring instrument, a frame, a rotating indicating member, a U shaped magnet having each of its arms engaging on one side and on one edge With adjacent faces on the frame, clamp means for holding said magnet in engagement with said faces whereby the spread of the magnet arms is uniformly maintained. Q

In testimony whereof I affix my signature.

JOSEPH ZUBATY. 

